By Keith Idec

LAS VEGAS – Marcus Browne showed he could cut it at the championship level Saturday night.

Browne out-boxed and bloodied Badou Jack on his way to producing the most impressive victory of his six-year pro career. The 2012 Olympian from Staten Island defeated Jack, a former super middleweight and light heavyweight champion, by unanimous decision in their 12-round, 175-pound title bout on the Manny Pacquiao-Adrien Broner undercard at MGM Grand Garden Arena.

His win earned Browne the WBA’s interim light heavyweight title and the WBC’s silver 175-pound championship.

The 28-year-old Browne (23-0, 16 KOs) was beating Jack handily before an accidental clash of heads caused one of the disgusting cuts imaginable in the middle of Jack’s forehead. The taller, skilled southpaw continued to pick apart Jack (22-2-3, 13 KOs), whose face was bloody for most of the final five-plus rounds.

All three judges – Eric Cheek (117-110), Max De Luca (116-111) and Don Trella (119-108) – scored Browne a wide winner in the final undercard bout Showtime Pay-Per-View televised before Pacquiao boxed Broner.

Las Vegas’ Jack was well behind on points prior to suffering that gross gash when their heads came together in the seventh round. Once he began bleeding badly from that long laceration, Jack just couldn’t mount much offense or defend himself well from Browne’s straight lefts.

Jack, 35, lost for the first time since Derek Edwards caught him cold in the first round and stopped him in their February 2014 fight in Verona, New York. The Stockholm, Sweden, native fought for the first time since settling for a draw with since-dethroned WBC light heavyweight champion Adonis Stevenson on May 19 in Toronto.

Brownehas won five consecutive fights since scoring a controversial, eight-round, split-decision victory over Radivoje Kalajdzic (24-1, 17 KOs) in April 2016 at Barclays Center in Brooklyn. None of the previous four opponents he beat since the Kalajdzic tested him were as good or as accomplished as Jack, though.

The lights went out at MGM Grand Garden Arena early in the 12th round, but the referee Tony Weeks was able to bring the boxers back together quickly because the lights weren’t out long.

Weeks called for a break with 1:54 to go in the 11th round. A ringside doctor took a close look at Jack, whose face was a bloody mess.

Fans cheered when Weeks allowed them to continue fighting.

Jack connected with a hard right hand about 35 seconds into the 10th round, as he maneuvered Browne into a neutral corner. A hard, straight left by Browne when there were 20 seconds to go was his best shot of the 10th round.

Browne had his way with Jack throughout the eighth round. Jack was having trouble seeing by then because blood flowed from a cut in the middle of his forehead, sustained in the previous round.

Jack’s left hook caught Browne about 20 seconds into the seventh round. Approximately a minute later, a hard, accidental clash of heads caused a long laceration in the middle of Jack’s forehead.

Weeks ordered a ringside physician to look at Jack’s cut before allowing the action to continue. Later in the seventh, Weeks took a point away from Browne for hitting Jack on a break.

Browne kept his distance during the sixth round and landed several straight left hands.

A fifth round full of clumsy clinches changed when there were about 40 seconds to go in it. That’s when Browne blasted Jack with a straight left hand that buzzed him and followed up with a thudding left to the Jack’s body.

Jack cracked Browne with a stiff jab about 30 seconds into the fourth round. Browne tried tying him up numerous times and mostly moved away from the stalking Jack for the rest of the fourth.

Jack tried to rough up Browne during the third round in an attempt to slow down the athletic southpaw. Weeks warned both boxers for questionable tactics at the midway mark of the third round.

Browne hit Jack with a straight left hand up top and followed it up by drilling Jack with a left to the body when there was just under 1:20 to go in the second round.

Browne established distance early in the first round. He landed a straight left hand with about 1:15 left in it and caught Jack with a short right hook late in that first round that knocked Jack off balance.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.